ME 360 Lab 4 – Post Lab Discussion Questions
Fall 2006
Please attach this to the back of your Lab 4 Data Sheet
Fun with Bode Plots
You are given the Bode plots of 2 motors by your boss and need to pick one of them for the
manufacturing plant. You measure the speed of the motors by the output voltage and have an
amplifier that can boost the signal by as much as 10 times. Which of the motors should you pick
if it will operate in the range of 0-50 RPM and your voltage measurement must be the same order
of magnitude as the voltage input. Because your boss is not a very good engineer, you will have
to show how and why you picked the motor.
-150
-100
-50
0
Magnitude (dB)
10-1 100101
270
315
360
405
450
Phase (deg)
Bode Diagram
Frequency (rad/sec)
Motor A
-60
-40
-20
0
20
40
Magnitude (dB)
10-1 100101102
-180
-135
-90
-45
0
Phase (deg)
Bode Diagram
Frequency (rad/sec)
Motor B
1
